Humidity fluctuations are a leading cause of damage in wooden constructions. In the case of glulam products, the multitude of possible layups concerning pith locations, diverse material properties across wood species, and the high computational cost associated with numerically simulating moisture diffusion and mechanical processes have constrained many research efforts to focus on one specific glulam layup and single wood species, consequently limiting the generalizability of the findings. To address this challenge, Monte Carlo simulations were employed to assess the significance of various factors. Based on which, two levels of simplification for are proposed. The first level reduces the multi-layer problem to a single-layer problem by applying appropriate boundary conditions. It substantial reduces the simulation costs and consequently allows faster sophisticated damage evolution modelling for specific glulam layup and wood species. The second level of simplification further reduces the problem to a single-element problem, enabling an analytical estimation of moisture stress. This level of simplification elucidates how factors such as moisture difference, material rotational angle, and other material properties impact stress. Most importantly, it facilitates a rapid estimation of the critical moisture variation range and the preferred sawing location of boards for different wood species, which provides guidance to the production of higher moisture resistant glulam products.